Stethoscopes are medical devices that capture, focus, and transmit sound waves produced by dynamic organs and vessels of humans or animals so that a clinician can hear and interpret the audible sounds produced by the organs or vessels. This process is termed auscultation and is a common means for diagnosis of pathologic conditions through detection of abnormal sounds that are characteristic for the disease states. In conventional stethoscopes, the microscopic movements of the diaphragm translate into increases in air pressure resulting in sound waves that travel through the tubing to the listener's ears. In contrast, electronic stethoscopes typically incorporate a microphone, capacitive sensor, or piezo-electric sensor juxtaposed to the stethoscope diaphragm that detect the acoustic waves for conversion into electrical signals for digitalization, filtration processing, and amplification. There are several advantages of the electronic stethoscopes, including digitalization of analog sound so that the sound data can be saved or transmitted via the internet to facilitate remote diagnostic capabilities in telemedicine. The electronic stethoscopes that utilize a microphone have traditionally suffered from excessive ambient noise detection and inefficient sound energy transfer. For instance, the “Digital Stethoscope” from http://www.thingiverse.com/thing:266767 shows a permanent enclosure of an earphone capable of recording pulmonary but not cardiac sounds. Likewise, the “MakerSenga” from http://www.thingiverse.com/thing:34110 is a fetal stethoscope that is conical in shape with a microphone placed at one end, which connects to the smartphone via a 3.5 mm port. The latter embodiment lacks a diaphragm and is significantly elongated and larger in size compared to a traditional chestpiece making it less portable than traditional stethoscopes.
The “iPhone Stethoscope Attachment” from http://www.thingiverse.com/thing:149028 shows an adapter that enables the attachment of the tubing of a conventional (non-electronic) stethoscope to the integrated microphone of iPhone 4 or 5. However, since the latter embodiment connects to lengthy tubing attached to the chestpiece of a stethoscope, a significant amount of the sound signal deteriorates prior to reaching the microphone of the iPhone. Furthermore, an intact stethoscope must be cut and essentially destroyed in order to create the digitized stethoscope. The limited quality of sound capture is apparent in the test recording on http://soundcloud.com/jeffthompson/3d-printed-iphone-stehoscope, which fails to demonstrate audible heart sounds.
The “Eko Core” from Eko Devices (https://ekodevices.com/) is also an attachment to the tubing of a conventional stethoscope. However, the latter embodiment differs from the “iPhone Stethoscope Attachment” in that it captures and digitizes sound for transmission via Bluetooth to a CPU utilizing device and offers the user to listen in analog or digital mode through the conventional stethoscope. As with the “iPhone Stethoscope Attachment,” the “Eko Core” requires the ownership and cutting (and therefore partial destruction) of the tube of a traditional stethoscope, which further adds to the cost of electronic device itself.
The “Steth IO” (release pending) from StratoScientific, Inc. (http://www.stethio.com/) is a smartphone case with an integrated stethoscope chestpiece and diaphragm, which also captures body sounds that are funneled to the microphone of the smartphone for “visualization, ambient noise reduction, and amplification.” The 3.5 mm port is accessible in the “Steth IO” so that body sounds can be heard through earphones, headsets, or speakers. However, since the diaphragm and chestpiece is fixed to the opposite side of the smartphone screen in its design, direct visualization of the real-time phonocardiogram displayed on the smartphone is limited by the user if the said user is an individual who was using the embodiment on oneself, e.g., for telemedicine purposes. Furthermore, since the StethIO utilizes the microphone integrated into the smartphone, it cannot not be connected directly to another CPU containing device such as a desktop or laptop computer.
The “Thinklabs One Digital Stethoscope” (http://www.thinklabs.com; U.S. Pat. No. 6,498,854 B1, PCT/US 2000/041633, US 2005/0058298 A1, US 2006/0018487 A1) is an electronic stethscope that consists of a chestpiece, which contains a capacitive plate that senses the vibrations of a capacitive Electromagnetic Diaphragm, thereby translating mechanical vibrations into audio signals through voltage changes. The latter embodiment can be used as a stand-alone stethoscope with a headset, or it can connect to a smartphone for capture and/or processing of the digitalized sound data. The body sounds can be heard and captured on the smartphone in real-time with a connection splitting adapter for the Thinklabs One Digital Stethoscope. Although the latter embodiment may produce superior sound quality with less ambient noise capture for digitalization, the production cost is likely to be significantly higher than attachments that funnel sound to an existing microphone. This may also be the case for the “CliniCloud Stethoscope” (https://clinicloud.com), which at the time of this writing has not yet been released.
There has been little or no development of a cost-efficient stethoscope adapter for the microphone of already existing earphones or headset listening device that will temporarily convert the microphone containing earphones or headset listening device attached to a CPU containing device into a electronic stethoscope capable of capturing the full range of bodily sounds, including lungs, heart, and bowel sounds with ambient noise reduction as well as simultaneous recording and listening capabilities of the digitalized sounds through earphones or headset listening device and real-time visualization on the CPU containing device such as a smartphone.